METAIRIE, La. >> Injuries have cost the Saints receiver Joseph Morgan and defensive end Kenyon Coleman for the season, depriving New Orleans of a top deep threat and a veteran run-stopper.

Morgan hurt his left knee in Saturday’s scrimmage, and coach Sean Payton said Wednesday his diagnosis has come back as a torn meniscus and partial tear of his anterior cruciate ligament.

Payton said Coleman, who left practice Tuesday, tore a pectoral muscle, which also requires season-ending surgery.

“Obviously they are losses,” Payton said. “We have to find some guys to step up and take their spot.”

Morgan’s injury was the latest setback in a tough year for the third-year receiver, who was arrested for drunk driving during the offseason.

An undrafted free agent out of NAIA Walsh University, Morgan now is expected to spend his second full season on injured reserve in his young career.

After a highlight-filled rookie preseason, he spent 2011 on injured reserve with a knee injury. In 2012, he emerged as one of the team’s top down-field targets, catching 10 passes for 379 yards and three TDs, a whopping 37.9 yards per reception. That performance was strong enough that the Saints allowed Devery Henderson to leave in free agency, making Morgan his heir apparent as the No. 3 receiver behind veterans Lance Moore and Marques Colston.

“You see how hard he has worked this offseason and you see how much he has improved and just how much he’s gaining that confidence,” Brees said of Morgan. “His role was there. Then all of a sudden that’s taken away.”

Morgan’s injury occurred when he was dragged down by safety Kenny Vaccaro, a first-round draft choice whose heavy collisions in mostly non-tackling practices has won praise from some defensive teammates but nearly led to a couple of scuffles.

Morgan has said on social media that Vaccaro should not be blamed for his injury, and other teammates chimed in Wednesday.

“Look, you love having that guy on your team,” right tackle Zach Strief said of Vaccaro. “Do we feel like he’s too physical sometimes in practice? Sure. But we feel the same way about some D-linemen and some linebackers, and they feel the same way about us.

“Kenny is who he is and I’m glad he’s on the team and I certainly wish that Joe was still with us, but it’s part of the game,” Strief continued. “I would never watch a guy make a legitimate football play and have someone get hurt and say, ‘It’s your fault.'”

Coleman was entering his 12th season after spending the past two with new Saints defensive coordinator Rob Ryan in Dallas, where he worked as a run-stopping end in Ryan’s 3-4 (three linemen, four linebackers) defense.

The 6-foot-5, 293-pound Coleman started 15 in 2011 but only five last season because of a torn triceps. The Saints hoped he would be a regular and provide veteran leadership as New Orleans switches its defensive alignment from the 4-3 scheme it has used for years.

“It stinks losing him,” said Strief, who has had to block Coleman in practice. “Good player, good teammate, good guy, a lot of knowledge. He’s helped me a lot in this camp just understanding how 3-4 guys play. … Losing any guy hurts but that’s the nature of the beast. … Somebody’s got to step up and someone’s going to get an opportunity to be successful like he was.”

The Saints still have depth at Coleman’s position, with Cameron Jordan, Akiem Hicks and Tom Johnson.

This week New Orleans signed veteran journeyman receiver Steve Breaston, who’ll compete for playing time with a host of young, inexperienced receivers including recent draft picks Nick Toon and Kenny Stills, as well as young free agents like Andy Tanner, Jarred Fayson and Preston Parker.

Free safety Malcolm Jenkins has gotten a good look at the young receivers from his side of scrimmage, and said it will be interesting to see what kind of chemistry they develop with the Saints’ star quarterback as the preseason wears on.

“The biggest plus is that we have Drew Brees,” Jenkins said. “He makes a lot of guys look good. And you’ve got some young guys really stepping up and playing pretty well.”